Tubular boiler



UNITED STATES PATENT OEEICE.

JAMES PIERPOINT, OF PITTSBURG, PENNSYLVANIA.

TUBULAR BOILER..

SPECIFICATION forming part of Letters Patent No. 472,660, dated April 12, 1892.

Application filed October 26,1891. Serial No. 409,302. (No model.)

To all whom it may concern.'

y Be it known that I, JAMES PIEEPOINT, of Pittsburg, in the county of Alleghenyand State of Pennsylvania, have invented a new and useful Improvement in Tubular Boilers, of which the following is a full, clear, andexl act description, reference being had to the accompanying drawings, in which- Figure 1 is a transverse vertical sectional View on the line I I of Fig. 2. Fig. 2 is a longitudinal sectional View on the line II II of Fig. 1, and Fig. 3 is a detached View of a segment of the drum at the points where the Water-pipes are connected therewith.

Like symbols of reference indicate like parts in each.

I will now proceed to describe my invention, so that others skilled in the art may manufacture and use the'same.

In the drawings, 2, 3, and 4 are the steam and' water drums, and 5 and 6 are the 1nuddrums. Extending from thebottom of the water-drum 2 to the topof the mud-drum 5 are a series of water-tubes 7, from the muddrum 5 to the water-drum 3 a series of tubes S, and from the Water-drum 4 to the mudto pass down between these tubes to the shelfv 16, from which point it passes up between the tubes 7 and in rear of the partition 17 to and against the drum 2. Themud-drums 5 and 6 may be connected with each other bythe water-tubes 18, and the Water-drums 3 and 4 may be connected with each other by a watertube 19. The drums2 and 3 and 3 and 4 are connected with each other by the steam-tubes 20 and 21. WVater is admitted to the drum 2 by the pipe 22 and thence passes through the tubes 7 to the mud-drums 5 and 6, and by the tubes 8 and 9 to the drums 3 and 4, and owing to this circulation and the location of the drums the sediment in the water is deposited in the mud-drums before the water passes to the drums 3 and 4, which are located in the hottest part of the furnace. Not only is this deposit of sediment more fully accomplished by my improvement than in prior boilers, but there is also a greater and more regular amount of heat imparted to the water con tained in the tubes and drums.

Heretofore in boilers of this class ithas been customary to employ water-tubes having a curve or bend at or near the point where the tubes are connected with the drums, as in order to obtain the necessary support the tubes must enter the drums on aline with the center. This curve, however, prevents the tubes from being'readily cleaned, and be-k sides this the tubes are not interchangeable with each other, and in order to replace a damaged tube one of special construction and shape must be furnished. To obviate this difficulty' and to permit of the use of straight tubes, which are easily cleaned and any one of which may be substituted for another, I

form a segment of the drums in the shape shown in Fig. 3, where the outer surface of the plate presents a plane surface and the inner conforms to the curvature of the drum. Owing to the plane outer surface, the tubes are readily attached to the plate, so that the tubes may be straight and parallel to each other, and at the same time, owing to the curvature of the inner surface, the strength of the drum is in no wlse impaired, as is the case where a segment of the drum is replaced by a flat plate, which plate can only be successfully held so as to resist the pressure of the steam by stays or other equally-obj ectionable means. This feature of the outer planesurfaced segment (shown in Fig. 3) I do not claim herein, as I am aware that the same is old in the art.

Having thus described my invention, what I claim is- A wateretube boiler consisting of the drums 2 3 4, having connecting-pipes, mud-drums 5 6, and water-tubes 7 3 9, in combination with the partition-walls 13 and 15, substantially as and for the purposes described.

In testimony whereof I have hereunto set my hand this 3th day of October, A. D. 1391.

JAMES PIERPOINT. Witnesses:

JAMES K. BAKEWELL, W. B. OoRwIN. 

